Aston Villa defenders Nathan Baker and Eric Lichaj are to stay with Lincoln until the New Year.
The duo, who signed initial one-month deals in late October, will remain on loan at Sincil Bank until 2nd January.
However, they will not be allowed to play in the FA Cup for the League Two side.
England Under-19 international centre-half Baker has played three times since his move.
American full-back Lichaj has featured just twice after the 20-year-old was sent off in the defeat at Morecambe.